I kind of like Smalltalk. Unfortunately syntax-wise Smalltalk is a huge set back and step back compared to Ruby. But Alan Kay's ideas are still epic today. I still don't think any language came close to his vision either; smalltalk definitely not. Ruby got closer but also no dice.

Elixir kind of got close too (prettier "erlang") - to have fault-tolerant mini-CPUs ("objects", aka similar to biological cells). The problem is that even people with grand ideas, such as Alan Kay, are not automatically great language designers. Matz is a better language designer than Alan Kay, for instance, whereas Alan Kay has the better ideas. It's a trade-off.

Note: I myself would not know how a language should look like that would follow Alan Kay's vision closer. It is definitely not smalltalk; it is also not ruby, though ruby is very good. I know I would suck as language designer, but as an improvement I would have a language similar to ruby (no, not crystal - crystal is a worse "ruby"), with a stronger focus on speed (perhaps have a second language that can be as fast as C here and be similar) and with a much stronger focus on what erlang brought to the table; that would get us close to, say, around 85% or 90%. And then add the rest that could fulfil Alan Kay's vision. Of course we need a specification too, because just saying "90% of his vision" is also pointless. I would perhaps start from erlang, retain the good bits, make it a modern variant of OOP (and OOP is also defined differently in different programming languages, so we need to define that term too, in the specification).

How is the syntax a step back? Smalltalk is the ultimate orthogonal language - everything is consistent. Famously the Smalltalk grammar fits on a postcard and tells you everything you need to know to understand the system from the source code.